Lung Health

The Lung Health Program

Western Reserve Hospital’s Lung Health Program is one of the only programs of its kind in Northeast Ohio. Unique is the inclusion of a lung cancer screening – made possible through a low-dose CT scan – which provides for highly effective early detection of cancers and abnormalities in the chest. Current and previous smokers, or those who have been exposed to secondhand smoke, receive varied and comprehensive treatment to evaluate lung health, determine steps to address possible health concerns and ensure that each patient gets the customized help needed to restore and preserve lung health for years to come.

Your Lungs

Lung Physiology

The lungs are a critical part of the cardiovascular system. The goal of the cardiovascular system is to pump oxygen-rich blood to the body's tissues and to transport carbon-dioxide-rich blood away from these tissues. The lungs are the place where carbon dioxide in the blood is exchanged for oxygen.

Physics of Breathing

Flow of air into and out of the lungs is controlled by changing the volume of the lungs, according to the Centers for Disease Control and Prevention (CDC). When a person inhales (also known as inspirations), muscles within the thorax (such as the diaphragm) contract. This expands the lungs, causing the air pressure within them to drop below that of the air outside the body. This causes air to enter the lungs until the pressure inside the lungs is equal to that of the atmosphere. With exhalation, other muscles in the abdomen contract, which causes the lungs to shrink, thus raising pressure and causing air to leave.

Lung Elasticity

The ability of the lungs to expand and contract as needed is partly due to their extreme elasticity. This is the result of cells called fibroblasts, according to a 2006 article published online in "GI Motility" ("Anatomy, Development, and Physiology of the Lungs"). These cells make connective tissue (including collagen), which is highly elastic. Not only is this elasticity necessary for the lungs to expand, it also makes exhalation easier, because the walls have a natural tendency to "spring back," which eases the shrinking of the lungs.


Alveoli are the cells within the lung that participate in gas exchange. According to the article in "GI Motility," approximately 300 million alveoli are within the lungs, giving the inside of the lungs a surface area of over ninety square meters. Alveoli are delicate, and are able to fill with air. In order to keep the alveoli from rupturing, some alveolar cells produce a chemical called surfactant, "The Anesthetist" explains. This chemical reduces the surface tension in the lungs so the expansion of the lung tissue does not tear the alveoli.


Gas exchange in the lungs works via the process of diffusion. Diffusion is another chemical tendency that causes substances to move from places of high concentration to places of lower concentration. It is similar to the way air moves from areas of high pressure to low pressure. Diffusion is able to allow oxygen to move from the air (where it is at a relatively high concentration) to the blood (which has little oxygen). Conversely, the blood is able to use diffusion to release some of the carbon dioxide back into the lungs.

Gas Exchange

Alveoli are in contact with thin blood vessels called capillaries. It is at the interface of the alveoli and capillaries that gas exchange occurs. The alveoli fill with air, and the oxygen in the air passes through the walls of the alveoli and into the capillaries. At the same time, carbon dioxide passes from the capillaries into the air-filled alveoli. This exchange of gases occurs quickly.